Fibonacci Heap

经过一下午的debug，总写出能运行的Fibonacci Heap了~

 

测试表明，运行的常数没有想象中的大。

和dijkstra配合的也不错，中小数据和二项堆表现几乎持平。

有待进一步大数据测试

 

 

#ifndef __FIB_HEAP__ #define __FIB_HEAP__ #include"PQ.h" template<class T> class fib_heap : public PQ<T>{ private: typedef pair<T,int> PTI; class node{ public: int idx; int degree; T key; node *left,*right,*child,*parent; bool mark; }; PTI* h; node** id; node* data; node *head,*min_node; int alloc_idx; int N; // number of trees node** in; // table for concatenating after deletion node* list_cat(node* a,node* b){ if(!a)return b; if(!b)return a; node *c=a->left,*d=b->right; c->right=d; d->left=c; a->left=b; b->right=a; return a; } node* list_remove(node* y){ y->parent=0; if(y->left==y)return 0; node *a=y->left,*b=y->right; a->right=b; b->left=a; y->right=y->left=y; return a; } node* link(node *x,node *y){ if(y->key < x->key) swap(x,y); head=list_remove(y); y->parent=x; x->degree++; x->child=list_cat(x->child,y); x->mark=0; return x; } void cut(node *e){ node *p; while(1){ if(!e->parent)return; p=e->parent; p->child=list_remove(e); p->degree--; head=list_cat(head,e); if(e->key < min_node->key) min_node=e; N++; if(!p->mark){ p->mark=1; return; }else{ p->mark=0; e=p; } } } public: fib_heap(int n){ data=new node[n]; id=new node*[n]; in=new node*[n]; memset(in,0,sizeof(node*)*n); alloc_idx=0; N=0; head=0; min_node=0; } ~fib_heap(){ delete[] data; delete[] id; delete[] in; } node* new_node(){ return &data[alloc_idx++]; } virtual bool empty(){ return !head; } virtual void insert(int i,const T& key){ id[i]=new_node(); id[i]->key=key; id[i]->idx=i; id[i]->degree=0; id[i]->parent=id[i]->child=0; id[i]->left=id[i]->right=id[i]; id[i]->mark=0; merge_with(id[i]); } void merge_with(node* a){ node *e=a,*m=a; do{ if(e->key < m->key) m=e; e=e->right; e->parent=0; N++; }while(e!=a); if(!min_node || m->key < min_node->key) min_node=m; head=list_cat(head,a); } virtual PTI min(){ return PTI(min_node->key,min_node->idx); } virtual int delete_min(){ int res=min_node->idx; node *children=min_node->child,*e,*next; head=list_remove(min_node); N=N-1+min_node->degree; int ct=N; if(children){ e=children; do{ e->parent=0; // going to merge into roots list, parent must be 0 e=e->right; }while(e!=children); head=list_cat(head,children); } if(!head)return res; e=head; next=e->right; while(1){ int d=e->degree; if(!in[d]){ in[d]=e; e=next; next=e->right; ct--; if(!ct)break; }else{ e=link(e,in[d]); N--; in[d]=0; } } e=head; min_node=e; do{ if(e->key < min_node->key) min_node=e; in[e->degree]=0; // reset each entry e=e->right; }while(e!=head); return res; } virtual void decrease_key(int i,const T& k){ node* e=id[i]; e->key=k; cut(e); } void print(node* a){ if(!a)return; node* e=a; do{ printf("%d(",e->key); print(e->child); printf(") "); e=e->right; }while(e!=a); } void print(){ print(head); putchar(10); } }; #endif